This invention pertains to systems for enabling the communication of signals and data between a musical instrument and electronic components needed to control and re-produce sounds generated by that instrument. More specifically, this invention relates to a system and method that facilitates the interconnection of one or more diverse musical instruments and related audio components on a universal network for purposes of communication of audio signals and signals to identify and control the devices.
The generation, transmission, amplification and control of audio signals and devices involves diverse yet interrelated technologies that are changing rapidly. The development and implementation of high bandwidth digital communication technologies and distribution systems is significantly affecting all media industries, from book publishing to television/video broadcasting. Products, systems, and services that affect the sense of sight or sound are converging in the use of common technologies and distribution pipelines. This has a profound effect, not only on the nature of the products that are produced, but on the sales channels and the nature of producing content for those products.
Current examples of the convergence of audio and digital technologies are the arrival and consumer acceptance of the MPEG-3 digital music format, the inexpensive recordable CD (e.g., the xe2x80x9cMiniDiscxe2x80x9d), and the high bandwidth Internet. However, the markets for technology-driven products are not served by implementation of multiple technical standards. Typically, a new technology begins in its early phase with multiple standards, which in many cases are vigorously debated and disputed among various advocates for the different standards. In most technology-driven industries that prosper, a single standard historically is universally adopted by members of that industry. Examples of such standardization include AC versus DC household electrical supply, Postscript printing language, and VHS versus Beta video recording format. Similarly, there is a need for a universally accepted standard for digital communication of audio and video content. Because of the overwhelming acceptance of the Internet and its TCP/IP protocol, coupled with a substantial pre-existing infrastructure of network hardware, software, and know-how, a universal standard for digital audio/video communication and control should revolve around this well-known TCP/IP and Internet technology.
The weakness of the existing audio hardware market is in its application of digital electronic technologies. Today""s musicians can record and process multi-tracks of high quality sound on their computers but are forced to plug into boxes with 1950""s era analog circuits. For example, the original challenge in the guitar musical instrument industry was to make the guitar louder. The circuits of the day distorted the sound of the instrument, but did accomplish their task. With time, these distortions became desirable tones, and became the basis of competition. Guitar players are very interested in sound modification.
Digital technology allows a musician to create an infinite variety of sound modifications and enhancements. The guitar player in a small club has a veritable arsenal of stomp boxes, reverb effects, wires, guitars and the like. He generally has a rack of effects boxes and an antiquated amplifier positioned somewhere where the sound distribution is generally not optimal because the amplifier is essentially a point source. Because of this lack of accurate sound placement, the sound technician is constantly struggling to integrate the guitar player into the overall sound spectrum, so as to please the rest of the band as well as the audience who would love to hear the entire ensemble.
Technology has made some progress along a digital audio path. For example, there are prior art guitar processors and digital amplifiers that use digital signal processing (DSP) to allow a single guitar to emulate a variety of different guitar types, amplifier types, and other sound modifications such as reverb and delay. To achieve the same variety of sounds and variations without using DSP technology, a musician would have to buy several guitars, several different amplifiers, and at least one, if not more than one, accessory electronic box.
All existing instruments, if they use a transducer of any kind, output the sound information as an analog signal. This analog signal varies in output level and impedance, is subject to capacitance and other environmental distortions, and can be subject to ground loops and other kinds of electronic noise. After being degraded in such fashion by the environment, the analog signal is often digitized at some point, with the digitized signal including the noise component. Although existing digital audio technologies show promise, it is clear that the audio equipment and musical instrument industries would benefit from a system and method where all audio signals are digital at inception.
At present, there are multiple digital interconnection specifications, including AES/EBU, S/PDIF, the ADAT xe2x80x9cLight Pipexe2x80x9d and IEEE 1394 xe2x80x9cFirewirexe2x80x9d. However, none of these standards or specifications are physically appropriate for the unique requirements of live musical performance. In addition, clocking, synchronization, and jitter/latency management are large problems with many of these existing digital options.
Different segments of the music market have experimented in digital audio. Some segments have completely embraced it, but there is no appropriate scalable standard. Clearly, digital components exist, but these are designed as digital xe2x80x9cislandsxe2x80x9d. Correspondingly, many manufacturers have chosen to make their small portion of the product world digital but rely mainly on traditional analog I/O to connect to the rest of the world. This may solve the local problem for the specific product in question, but does little to resolve the greater system-oriented issues that arise as the number of interconnected devices grows. In addition, the small sound degradation caused by a analog-to-digital and digital-to-analog transformation in each xe2x80x9cboxxe2x80x9d combines to produce non-optimal sound quality. Finally, the cost, power and size inefficiency related to having each component in a chain converting back and forth to digital begs for a universal, end-to-end digital solution.
Another basic yet important part of the problem is that live musicians need a single cable that is long, locally repairable, and simple to install and use. In addition, it is highly desirable to support multiple audio channels on a single cable, as setups often scale out of control with current multiple cable solutions. Also, phantom power is preferred over batteries as means to power the active circuits used in digital instruments.
Based on the technology trends and patterns that have already been established, a digital guitar will emerge with the transducers (pick-ups) feeding a high bandwidth digital signal. This advance will remove many detrimental aspects of the analog technology it will replace, including noise, inconsistent tonal response from time to time, and loss of fidelity with a need for subsequent signal processing. The introduction of digital technology from the instrument will allow the entire signal path and the equipment associated with the signal path to be digital. Unfortunately, there is no system available that will easily and quickly interconnect multiple musical instruments and associated audio components so that they can communicate with each other and be controlled entirely in the digital domain, using a universal interface and communications protocol.
Performing musicians need a new, performance-oriented solution that provides multiple channels of advanced fidelity audio, intuitive control capabilities, extreme simplicity and total reliability. It is also desirable for this system to be scalable to meet the requirements of permanent installations, including recording studio applications.
To overcome the limitations and weaknesses of existing analog and digital technologies in the musical performance environment, applicant has invented a system that will allow, in a preferred embodiment, up to sixteen (16) channels of 32 bitxe2x80x9496 kHz digital audio signals and data to flow over a single cable in both directions, using inexpensive connectors and cables already available and in use in virtually every computer network. This cable will also carry sufficient power to allow the electronics in the guitar (or other instrument) to function without a battery or other power source. For convenience, the system of the present invention will sometimes be referred herein as the Global Musical Instrument Communications System (or GMICS). GMICS is a trademark of the assignee of the present invention, Gibson Guitar Corp.
The system of this invention includes the GMICS data link, a high-speed point-to-point connection for communication of digital audio data between two GMICS devices. The system and method of the invention further includes definitions and description of the characteristics of individual GMICS devices as well as GMICS system configuration and control protocols.
The GMICS data link is a high-speed point-to-point connection transmitting full-duplex digital audio signals, control signals, and user data between two interconnected GMICS devices. Self-clocking data are packed in frames that are continuously transmitted between GMICS devices at the current sample rate.
Flexible packing of digital audio data within a frame allows a tradeoff between bit resolution and channel capacity to optimize the fit and interface for GMICS devices having diverse characteristics. A Control data field provides for GMICS system configuration, device identification, control, and status. User data fields are provided for transmitting non-audio data between GMICS devices.
A GMICS system may include two types of GMICS devicesxe2x80x94xe2x80x9cinstrumentsxe2x80x9d and xe2x80x9ccontrollers.xe2x80x9d An instrument is typically a sound transducer such as a guitar, microphone, or speaker. A controller is typically an intelligent amplifier that provides connections and power for multiple GMICS instruments, and is capable of, and responsible for, configuring the GMICS system. Controllers may also include upstream and downstream connections to other controllers for increased instrument connectivity.
Data link electronics and associated cabling and connectors are designed for reliable use in harsh environments. xe2x80x9cHot-pluggingxe2x80x9d of GMICS devices is supported by the system.
Accordingly, a Universal Communications and Control System for Amplified Musical Instruments is provided that includes the following novel features:
(1) The Control data for each device includes a xe2x80x9cFriendly namingxe2x80x9d scheme using a Device ID so that: (a) there is an automatic configuration by, and synchronization to, the system by the identifying device; (b) the use of a xe2x80x9cFriendly namexe2x80x9d allows the user to name his device on the system; (c) the xe2x80x9cdevice namexe2x80x9d resides in the device, not in a data base; and (d) the device ID is available when the device is plugged into a xe2x80x98foreignxe2x80x99 GMICS system.
(2) A bi-directional device interface is provided that adds xe2x80x9cresponsexe2x80x9d to the existing instrument stimulus to create a full duplex instrument that is able to display and react to other devices in the system.
(3) The system topology allows for nodal connection of resources so that instruments and control devices plug in to create the desired system complexity and allowing for simple system enhancement by plugging in a new device with the desired features.
(4) The system implements dynamic resource allocation, including: (a) routing of audio and control signals xe2x80x9con the flyxe2x80x9d; (b) audio nodes can be xe2x80x98movedxe2x80x99 at will; and (c) special effects devices can be shared with out physically moving or connecting them.
(5) Logical connections are made to the system so that a device can be physically connected into the system through any available connector, e.g., a guitar does not have to be directly plugged into the guitar amplifier.
(6) The system has a multi-layered protocol that supports many different physical transport media and allows for simple expansion of both the number of audio channels and the data bandwidth.
(7) There can be a familiar looking (to the user) point to point connection of devices, or a xe2x80x9cstarxe2x80x9d network (analogous to a xe2x80x9cbreakout boxxe2x80x9d) configuration for multiple devices, thereby simplifying the user experience.
(8) The system can operate at multiple sampling rates so that different GMICS data links operate at different sample rates within the system.
(9) Phantom power for instrument electronics is delivered over the GMICS data link.
(10) The system can take advantage of conventional network hardware, e.g., one embodiment of a GMICS system is implemented over a 100 megabit Ethernet physical layer using standard Category 5 (CAT5) cable
Thus, GMICS is the first low-cost digital interconnection system based on a universal standard that is appropriate for use in the live, professional, studio and home music performance environments. GMICS technology can be quickly adapted for use in musical instruments, processors, amplifiers, recording devices, and mixing devices.
GMICS overcomes the limitations and performance liabilities inherent in current xe2x80x9cpoint solutionxe2x80x9d digital interfaces and creates a completely digital system that offers enhanced sonic fidelity, simplified setup and usage while providing new levels of control and reliability.
GMICS enables musical instruments and their supporting devices such as amplifiers, mixers, and effect boxes from different vendors to digitally inter-operate in an open-architecture infrastructure.